Genetic correlation

Estimates of genetic parameters for total milk yield over multiple ages in Brazilian Murrah buffaloes using different models

R. C. Sesana, Baldi, F., Borquis, R. R. A., Bignardi, A. B., Hurtado-Lugo, N. A., L. Faro, E., Albuquerque, L. G., and Tonhati, H., Estimates of genetic parameters for total milk yield over multiple ages in Brazilian Murrah buffaloes using different models, vol. 13, pp. 2784-2795, 2014.

The objective of this study was to estimate variance components and genetic parameters for accumulated 305-day milk yield (MY305) over multiple ages, from 24 to 120 months of age, applying random regression (RRM), repeatability (REP) and multi-trait (MT) models. A total of 4472 lactation records from 1882 buffaloes of the Murrah breed were utilized. The contemporary group (herd-year-calving season) and number of milkings (two levels) were considered as fixed effects in all models.

Use of weaning management group as a random effect for a more robust estimation of genetic parameters for post-weaning traits in Nellore cattle

V. B. Pedrosa, Eler, J. P., Ferraz, J. B. S., and Groeneveld, E., Use of weaning management group as a random effect for a more robust estimation of genetic parameters for post-weaning traits in Nellore cattle, vol. 13, pp. 7013-7021, 2014.

Data from 69,525 animals were used to compare two types of analyses, one of them having the weaning management group (WEMANG) included as an effect in the contemporary group (F_WEMANG) and the other considering the weaning management group as a random effect, not related to the mathematical model (R_WEMANG) for post-weaning traits.

(Co)variance components and genetic parameters for growth traits in Arabi sheep using different animal models

B. Shokrollahi and Baneh, H., (Co)variance components and genetic parameters for growth traits in Arabi sheep using different animal models, vol. 11, pp. 305-314, 2012.

The objective of the present study was to estimate genetic parameters for body weight at different ages in Arabi sheep using data collected from 1999 to 2009. Investigated traits consisted of birth weight (N = 2776), weaning weight (N = 2002) and weight at six months of age (N = 1885). The data were analyzed using restricted maximum likelihood analysis, by fitting univariate and multivariate animal models. All three weight traits were significantly influenced by birth year, sex and birth type. Age of dam only significantly affected birth weight.

Additive genetic relationship of longevity with fertility and production traits in Nellore cattle based on bivariate models

M. H. Van Melis, Oliveira, H. N., Eler, J. P., Ferraz, J. B. S., Casellas, J., and Varona, L., Additive genetic relationship of longevity with fertility and production traits in Nellore cattle based on bivariate models, vol. 9, pp. 176-187, 2010.

Survival or longevity is an economically important trait in beef cattle. The main inconvenience for its inclusion in selection criteria is delayed recording of phenotypic data and the high computational demand for including survival in proportional hazard models. Thus, identification of a longevity-correlated trait that could be recorded early in life would be very useful for selection purposes.

Correspondence between performance of Eucalyptus spp trees selected from family and clonal tests

C. A. F. Reis, Gonçalves, F. M. A., Rosse, L. N., Costa, R. R. G. F., and Ramalho, M. A. P., Correspondence between performance of Eucalyptus spp trees selected from family and clonal tests, vol. 10, pp. 1172-1179, 2011.

We examined the correspondence in performance between trees selected from a family test and their respective clones from a clonal test of Eucalyptus. Full-sib families were obtained from controlled pollination among individuals of Eucalyptus grandis and between E. grandis and E. urophylla. The hybridizations did not follow a factorial scheme. The family tests were carried out at three locations in Eunápolis and Itabela counties, in Bahia, Brazil, in 2003.

Genetic evaluation of Jatropha curcas: an important oilseed for biodiesel production

R. G. Freitas, Missio, R. F., Matos, F. S., Resende, M. D. V., and Dias, L. A. S., Genetic evaluation of Jatropha curcas: an important oilseed for biodiesel production, vol. 10, pp. 1490-1498, 2011.

Jatropha curcas, internationally and locally known, respectively, as physic nut and pinhão manso, is a highly promising species for biodiesel production in Brazil and other countries in the tropics. It is rustic, grows in warm regions and is easily cultivated. These characteristics and high-quality oil yields from the seeds have made this plant a priority for biodiesel programs in Brazil. Consequently, this species merits genetic investigations aimed at improving yields. Some studies have detected genetic variability in accessions in Africa and Asia.

Genetic and environmental factors that influence production and quality of milk of Alpine and Saanen goats

L. F. Brito, Silva, F. G., Melo, A. L. P., Caetano, G. C., Torres, R. A., Rodrigues, M. T., and Menezes, G. R. O., Genetic and environmental factors that influence production and quality of milk of Alpine and Saanen goats, vol. 10, pp. 3794-3802, 2011.

Data from 1279 lactations of 783 Alpine and Saanen goats of the herd of our university in Minas Gerais, Brazil, were used to study environmental effects on and to estimate genetic parameters for milk production until 270 days of lactation (MP270) and for production and percentages of fat (PFAT and %FAT), protein (PPROT and %PROT), lactose (PLACT and %LACT), and total dry extract (PEXTR and %EXTR). Environmental effects were estimated by a statistical model that included contemporary group effect, type of kidding, genetic grouping, and kidding order.

Genetic correlation between heifer pregnancy and scrotal circumference measured at 15 and 18 months of age in Nellore cattle

J. P. Eler, Mattos, E. C., Mourão, G. B., Ferraz, J. B. S., and Balieiro, J. C. C., Genetic correlation between heifer pregnancy and scrotal circumference measured at 15 and 18 months of age in Nellore cattle, vol. 5, pp. 569-580, 2006.

Data of pregnancy diagnosis from 24,945 Nellore heifers, raised under tropical conditions in Brazil and exposed to breeding at about 14 months of age, were analyzed simultaneously with 13,742 (analysis 1), 36,091 (analysis 2), 8,405 (analysis 3), and 8,405 (analysis 4) scrotal circumference (SC) records of contemporary young bulls in order to estimate heritability (h2) for yearling heifer pregnancy (HP) and for SC measured at around 15 (SC15) and 18 (SC18) months of age and to estimate genetic correlation between HP and SC15 (SC18).

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